Witnessing Evaporation
The engineers at Splash Engineering (the students) have been commissioned by Thirsty County to conduct a study of evaporation and transpiration in their region. During one week, students observe and measure (by weight) the ongoing evaporation of water in pans set up with different variables, and then assess what factors may affect evaporation. Variables include adding to the water an amount of soil and an amount of soil with growing plants.
Evaporation and transpiration create clouds, as part of the Earth's water cycle.Copyright Agency for Toxic Substances & Disease Registry, Centers for Disease Control and Prevention, US Department of Health and Human Services http://www.atsdr.cdc.gov/sites/vieques/groundwater.html
Engineers consider evaporation in the design and operation of dams, and it is an important factor in the site selection and operation of dams because of its potential to cause substantial water loss, especially in hot and arid environments. Typically, engineers and hydrologists use computer models and spreadsheets to estimate a reservoir's water "budget," taking into account the effects of evaporation on its storage. The information from an evaporation study provides the water budget with more accurate regional estimates of expected water loss due to evaporation and transpiration.
After this activity, students should be able to:
- Define evaporation and transpiration.
- Describe how soil helps retain water to be available for plants.
- Recongize that evaporation is an important consideration in the design and operation of dams